68 BULLETIN 91, UNITED STATES NATIONAL MUSEUM. 



in a single oyster. In most instances the crab was found well thrust 

 in between the palps, usually between the middle ones. This is evi- 

 dently annoying to the oyster, for the palps sometimes show thick- 

 ened outgrowths, or are malformed and stunted in size. To what 

 extent the crab is of value to the oyster, as commonly supposed, is 

 debatable. The oyster is said to feed on clusters of bell-animalcules 

 (Zoothamnium) , which are attached to the crab;i on the other hand, 

 the food of the crab, as evidenced by its stomach contents, consists in 

 great part of such minute organisms as are sought by the host, in 

 addition to many small crustaceans not normally the oyster's pre3\ 



Range. — Salem, Massachusetts, to Micco, Florida; Guadeloupe 

 (Desbonne). 



Material examined. — 



New York Bay; from oysters; E. G. Blackford; 74 females (2542). 



New York market; from oysters; E. G. Blackford; 26 females 

 (4991). 



West coast of Chesapeake Bay, Northumberland County, Vir- 

 ginia; December 23, 1914; P. L. Boone; 4 females (49208). 



Eappahannock Eiver, Virginia; in oysters; A. C. Weed; 6 females 

 (42512). 



Out of Lynn Haven oysters, Virginia ; November 29, 1905 ; Bureau 

 of Fisheries; 2 females (49210). 



Beaufort, North Carolina ; Union College Coll. ; 1 male, young, 

 depos. in U.S.N.M. (49209). 



Winyah Bay, South Carolina: December, 1890; station 54; 

 steamer /^2sA Hawk; 5 females (18214). December 31, 1890; station 

 5G; steamer Fish Ilawh; 6 females (18215). One-half mile north of 

 wharf on South Island; dredged; Sh. ; temp. 49.5° F., January 3, 

 1891; stations 1G41, 1G42; steamer Fish Hawk; 1 female (18213). 



Clam Bank Creek, South Carolina; from oysters; December 30, 

 1890; steamer Fish Hawk; 3 females (1821C). 



Charleston, South Carolina; from a starfish; Louis Agassiz; 1 

 female, 3 mm. long, mature (5730, M.C.Z.). 



Colleton River, South Carolina; 1891; steamer Fish Haiok; 7 

 females (26108). 



East peninsula opposite Micco, Florida; O. Bangs; 8 females 

 (3 ovig.) (18740). 



PINNOTHERES HOLMESI," new species. 

 Plate 15, figs. 1-2. 

 t Pinnotheres nudus Weymouth, Lelnnd Stanford Jr. Univ. Pnbl., Univ. 

 Ser. No. 4, 1910, p. 53, fig. 1 ( ?) ; not P. midus Holmes, 1895. 



Type-locality.— 1 Pacific Grove, California; 1 female ovig., holo- 

 type (Mus. Stanford Univ.). 



1 Ryder, Rept. Maryland Fish Commission for 1880 (1881), p. 24. 

 = Named for Dr. S. J. Holmes, of the University of California. 



